<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta http-equiv="X-UA-Compatible" content="ie=edge" />
    <title>Document</title>
  </head>
  <body>
    hello,
    <span id="name"></span>
    <script>
      let obj = {};
      Object.defineProperty(obj, 'name', {
        get: function() {
          return document.getElementById('name').innerHTML;
        },
        set: function(txt) {
          document.getElementById('name').innerHTML = txt;
        }
      });
      console.log('初始name:', obj.name);
      obj.name = '小菠萝';
      console.log('设置后的name:', obj.name);
      
    </script>
  </body>
</html>
